HBASE-19131 Add the ClusterStatus hook and cleanup other hooks which can be replaced by ClusterStatus hook

hbase-client/src/main/java/org/apache/hadoop/hbase/ClusterStatus.java

@@ -19,6 +19,7 @@
 
 package org.apache.hadoop.hbase;
 
+import com.google.common.base.Objects;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collection;
@@ -194,14 +195,14 @@ public class ClusterStatus extends VersionedWritable {
     if (!(o instanceof ClusterStatus)) {
       return false;
     }
-    return (getVersion() == ((ClusterStatus)o).getVersion()) &&
+    ClusterStatus other = (ClusterStatus) o;
-      getHBaseVersion().equals(((ClusterStatus)o).getHBaseVersion()) &&
+    return Objects.equal(getHBaseVersion(), other.getHBaseVersion()) &&
-      this.liveServers.equals(((ClusterStatus)o).liveServers) &&
+        Objects.equal(this.liveServers, other.liveServers) &&
-      this.deadServers.containsAll(((ClusterStatus)o).deadServers) &&
+        getDeadServerNames().containsAll(other.getDeadServerNames()) &&
-      Arrays.equals(this.masterCoprocessors,
+        Arrays.equals(getMasterCoprocessors(), other.getMasterCoprocessors()) &&
-                    ((ClusterStatus)o).masterCoprocessors) &&
+        Objects.equal(getMaster(), other.getMaster()) &&
-      this.master.equals(((ClusterStatus)o).master) &&
+        getBackupMasters().containsAll(other.getBackupMasters()) &&
-      this.backupMasters.containsAll(((ClusterStatus)o).backupMasters);
+        Objects.equal(getClusterId(), other.getClusterId());
   }
 
   /**

hbase-client/src/main/java/org/apache/hadoop/hbase/ServerLoad.java

@@ -20,6 +20,7 @@
 
 package org.apache.hadoop.hbase;
 
+import com.google.common.base.Objects;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.classification.InterfaceStability;
 import org.apache.hadoop.hbase.protobuf.ProtobufUtil;
@@ -329,4 +330,35 @@ public class ServerLoad {
   public long getReportTime() {
     return reportTime;
   }
+
+  @Override
+  public int hashCode() {
+    return Objects.hashCode(stores, storefiles, storeUncompressedSizeMB,
+        storefileSizeMB, memstoreSizeMB, storefileIndexSizeMB, readRequestsCount,
+        writeRequestsCount, rootIndexSizeKB, totalStaticIndexSizeKB,
+        totalStaticBloomSizeKB, totalCompactingKVs, currentCompactedKVs);
+  }
+
+  @Override
+  public boolean equals(Object other) {
+    if (other == this) {
+      return true;
+    }
+    if (other instanceof ServerLoad) {
+      ServerLoad sl = ((ServerLoad) other);
+      return stores == sl.stores && storefiles == sl.storefiles
+          && storeUncompressedSizeMB == sl.storeUncompressedSizeMB
+          && storefileSizeMB == sl.storefileSizeMB
+          && memstoreSizeMB == sl.memstoreSizeMB
+          && storefileIndexSizeMB == sl.storefileIndexSizeMB
+          && readRequestsCount == sl.readRequestsCount
+          && writeRequestsCount == sl.writeRequestsCount
+          && rootIndexSizeKB == sl.rootIndexSizeKB
+          && totalStaticIndexSizeKB == sl.totalStaticIndexSizeKB
+          && totalStaticBloomSizeKB == sl.totalStaticBloomSizeKB
+          && totalCompactingKVs == sl.totalCompactingKVs
+          && currentCompactedKVs == sl.currentCompactedKVs;
+    }
+    return false;
+  }
 }

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ConnectionManager.java

@@ -1807,13 +1807,6 @@ class ConnectionManager {
           return stub.clearDeadServers(controller, request);
         }
 
-        @Override
-        public MasterProtos.ListDeadServersResponse listDeadServers(
-            RpcController controller,
-            MasterProtos.ListDeadServersRequest request) throws ServiceException {
-          return stub.listDeadServers(controller, request);
-        }
-
         @Override
         public AddColumnResponse addColumn(RpcController controller, AddColumnRequest request)
         throws ServiceException {
@@ -2721,7 +2714,7 @@ class ConnectionManager {
     public boolean hasCellBlockSupport() {
       return this.rpcClient.hasCellBlockSupport();
     }
-    
+
     @Override
     public ConnectionConfiguration getConnectionConfiguration() {
       return this.connectionConfig;

hbase-client/src/main/java/org/apache/hadoop/hbase/client/HBaseAdmin.java

@@ -136,7 +136,6 @@ import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.IsRestoreSnapshot
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.IsRestoreSnapshotDoneResponse;
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.IsSnapshotDoneRequest;
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.IsSnapshotDoneResponse;
-import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.ListDeadServersRequest;
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.ListNamespaceDescriptorsRequest;
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.ListProceduresRequest;
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.ListTableDescriptorsByNamespaceRequest;
@@ -4903,14 +4902,7 @@ public class HBaseAdmin implements Admin {
 
   @Override
   public List<ServerName> listDeadServers() throws IOException {
-    return executeCallable(new MasterCallable<List<ServerName>>(getConnection()) {
+    return new ArrayList<>(getClusterStatus().getDeadServerNames());
-      @Override
-      public List<ServerName> call(int callTimeout) throws ServiceException {
-        ListDeadServersRequest req = ListDeadServersRequest.newBuilder().build();
-        return ProtobufUtil.toServerNameList(
-                master.listDeadServers(null, req).getServerNameList());
-      }
-    });
   }
 
   @Override

hbase-protocol/src/main/protobuf/Master.proto

@@ -556,13 +556,6 @@ message SecurityCapabilitiesResponse {
   repeated Capability capabilities = 1;
 }
 
-message ListDeadServersRequest {
-}
-
-message ListDeadServersResponse {
-  repeated ServerName server_name = 1;
-}
-
 message ClearDeadServersRequest {
   repeated ServerName server_name = 1;
 }
@@ -867,9 +860,4 @@ service MasterService {
   /** clear dead servers from master*/
   rpc ClearDeadServers(ClearDeadServersRequest)
     returns(ClearDeadServersResponse);
-
-  /** Returns a list of Dead Servers. */
-  rpc ListDeadServers(ListDeadServersRequest)
-    returns(ListDeadServersResponse);
-
 }

hbase-rsgroup/src/main/java/org/apache/hadoop/hbase/rsgroup/RSGroupAdminEndpoint.java

@@ -31,6 +31,7 @@ import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
 
+import org.apache.hadoop.hbase.ClusterStatus;
 import org.apache.hadoop.hbase.Coprocessor;
 import org.apache.hadoop.hbase.CoprocessorEnvironment;
 import org.apache.hadoop.hbase.HColumnDescriptor;
@@ -953,15 +954,13 @@ public class RSGroupAdminEndpoint extends RSGroupAdminService
   }
 
   @Override
-  public void preListDeadServers(ObserverContext<MasterCoprocessorEnvironment> ctx)
+  public void preGetClusterStatus(ObserverContext<MasterCoprocessorEnvironment> ctx)
       throws IOException {
-
   }
 
   @Override
-  public void postListDeadServers(ObserverContext<MasterCoprocessorEnvironment> ctx)
+  public void postGetClusterStatus(ObserverContext<MasterCoprocessorEnvironment> ctx,
-      throws IOException {
+      ClusterStatus status) throws IOException {
-
   }
 
   @Override

hbase-server/src/main/jamon/org/apache/hadoop/hbase/tmpl/master/BackupMasterStatusTmpl.jamon

@@ -54,7 +54,8 @@ MasterAddressTracker masterAddressTracker = master.getMasterAddressTracker();
         <th>Start Time</th>
     </tr>
     <%java>
-    Collection<ServerName> backup_masters = master.getClusterStatus().getBackupMasters();
+    Collection<ServerName> backup_masters
+      = master.getClusterStatusWithoutCoprocessor().getBackupMasters();
     ServerName [] backupServerNames = backup_masters.toArray(new ServerName[backup_masters.size()]);
     Arrays.sort(backupServerNames);
     for (ServerName serverName : backupServerNames) {

hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/BaseMasterAndRegionObserver.java

@@ -19,6 +19,7 @@
 
 package org.apache.hadoop.hbase.coprocessor;
 
+import org.apache.hadoop.hbase.ClusterStatus;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.classification.InterfaceStability;
 import org.apache.hadoop.hbase.HBaseInterfaceAudience;
@@ -67,12 +68,13 @@ public class BaseMasterAndRegionObserver extends BaseRegionObserver
   }
 
   @Override
-  public void preListDeadServers(ObserverContext<MasterCoprocessorEnvironment> ctx)
+  public void preGetClusterStatus(ObserverContext<MasterCoprocessorEnvironment> ctx)
     throws IOException {
   }
 
   @Override
-  public void postListDeadServers(ObserverContext<MasterCoprocessorEnvironment> ctx)
+  public void postGetClusterStatus(ObserverContext<MasterCoprocessorEnvironment> ctx,
+      ClusterStatus status)
     throws IOException {
   }
 

hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/BaseMasterObserver.java

@@ -19,6 +19,7 @@
 
 package org.apache.hadoop.hbase.coprocessor;
 
+import org.apache.hadoop.hbase.ClusterStatus;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.classification.InterfaceStability;
 import org.apache.hadoop.hbase.HBaseInterfaceAudience;
@@ -78,13 +79,14 @@ public class BaseMasterObserver implements MasterObserver {
   }
 
   @Override
-  public void preListDeadServers(ObserverContext<MasterCoprocessorEnvironment> ctx)
+  public void preGetClusterStatus(ObserverContext<MasterCoprocessorEnvironment> ctx)
-    throws IOException {
+      throws IOException {
   }
 
   @Override
-  public void postListDeadServers(ObserverContext<MasterCoprocessorEnvironment> ctx)
+  public void postGetClusterStatus(ObserverContext<MasterCoprocessorEnvironment> ctx,
-    throws IOException {
+      ClusterStatus status)
+      throws IOException {
   }
 
   @Override
@@ -474,7 +476,7 @@ public class BaseMasterObserver implements MasterObserver {
   public void postListSnapshot(final ObserverContext<MasterCoprocessorEnvironment> ctx,
       final SnapshotDescription snapshot) throws IOException {
   }
-  
+
   @Override
   public void preCloneSnapshot(final ObserverContext<MasterCoprocessorEnvironment> ctx,
       final SnapshotDescription snapshot, final HTableDescriptor hTableDescriptor)

hbase-server/src/main/java/org/apache/hadoop/hbase/coprocessor/MasterObserver.java

@@ -23,6 +23,7 @@ import java.io.IOException;
 import java.util.List;
 import java.util.Set;
 
+import org.apache.hadoop.hbase.ClusterStatus;
 import org.apache.hadoop.hbase.classification.InterfaceAudience;
 import org.apache.hadoop.hbase.classification.InterfaceStability;
 import org.apache.hadoop.hbase.Coprocessor;
@@ -674,7 +675,7 @@ public interface MasterObserver extends Coprocessor {
    */
   void postListSnapshot(final ObserverContext<MasterCoprocessorEnvironment> ctx,
       final SnapshotDescription snapshot) throws IOException;
-  
+
   /**
    * Called before a snapshot is cloned.
    * Called as part of restoreSnapshot RPC call.
@@ -921,7 +922,7 @@ public interface MasterObserver extends Coprocessor {
    */
   void postTableFlush(final ObserverContext<MasterCoprocessorEnvironment> ctx,
       final TableName tableName) throws IOException;
-  
+
   /**
    * Called before the quota for the user is stored.
    * @param ctx the environment to interact with the framework and master
@@ -1027,7 +1028,7 @@ public interface MasterObserver extends Coprocessor {
       final String namespace, final Quotas quotas) throws IOException;
 
   /**
-   * Called before dispatching region merge request. 
+   * Called before dispatching region merge request.
    * It can't bypass the default action, e.g., ctx.bypass() won't have effect.
    * @param ctx coprocessor environment
    * @param regionA first region to be merged
@@ -1036,7 +1037,7 @@ public interface MasterObserver extends Coprocessor {
    */
   void preDispatchMerge(final ObserverContext<MasterCoprocessorEnvironment> ctx,
       HRegionInfo regionA, HRegionInfo regionB) throws IOException;
-  
+
   /**
    * called after dispatching the region merge request.
    * @param c coprocessor environment
@@ -1048,14 +1049,15 @@ public interface MasterObserver extends Coprocessor {
       final HRegionInfo regionA, final HRegionInfo regionB) throws IOException;
 
   /**
-   * Called before list dead region servers.
+   * Called before get cluster status.
    */
-  void preListDeadServers(ObserverContext<MasterCoprocessorEnvironment> ctx) throws IOException;
+  void preGetClusterStatus(ObserverContext<MasterCoprocessorEnvironment> ctx) throws IOException;
 
   /**
-   * Called after list dead region servers.
+   * Called after get cluster status.
    */
-  void postListDeadServers(ObserverContext<MasterCoprocessorEnvironment> ctx) throws IOException;
+  void postGetClusterStatus(ObserverContext<MasterCoprocessorEnvironment> ctx,
+      ClusterStatus status) throws IOException;
 
   /**
    * Called before clear dead region servers.

hbase-server/src/main/java/org/apache/hadoop/hbase/master/HMaster.java

@@ -828,7 +828,7 @@ public class HMaster extends HRegionServer implements MasterServices, Server {
 
     //initialize load balancer
     this.balancer.setMasterServices(this);
-    this.balancer.setClusterStatus(getClusterStatus());
+    this.balancer.setClusterStatus(getClusterStatusWithoutCoprocessor());
     this.balancer.initialize();
 
     // Check if master is shutting down because of some issue
@@ -860,7 +860,7 @@ public class HMaster extends HRegionServer implements MasterServices, Server {
     this.assignmentManager.joinCluster();
 
     // set cluster status again after user regions are assigned
-    this.balancer.setClusterStatus(getClusterStatus());
+    this.balancer.setClusterStatus(getClusterStatusWithoutCoprocessor());
 
     // Start balancer and meta catalog janitor after meta and regions have been assigned.
     status.setStatus("Starting balancer and catalog janitor");
@@ -1488,7 +1488,7 @@ public class HMaster extends HRegionServer implements MasterServices, Server {
       List<RegionPlan> plans = new ArrayList<RegionPlan>();
 
       //Give the balancer the current cluster state.
-      this.balancer.setClusterStatus(getClusterStatus());
+      this.balancer.setClusterStatus(getClusterStatusWithoutCoprocessor());
       for (Entry<TableName, Map<ServerName, List<HRegionInfo>>> e : assignmentsByTable.entrySet()) {
         List<RegionPlan> partialPlans = this.balancer.balanceCluster(e.getKey(), e.getValue());
         if (partialPlans != null) plans.addAll(partialPlans);
@@ -2404,10 +2404,22 @@ public class HMaster extends HRegionServer implements MasterServices, Server {
     }
   }
 
+  public ClusterStatus getClusterStatus() throws IOException {
+    if (cpHost != null) {
+      cpHost.preGetClusterStatus();
+    }
+    ClusterStatus status = getClusterStatusWithoutCoprocessor();
+    LOG.info(getClientIdAuditPrefix() + " get ClusterStatus, status=" + status);
+    if (cpHost != null) {
+      cpHost.postGetClusterStatus(status);
+    }
+    return status;
+  }
+
   /**
    * @return cluster status
    */
-  public ClusterStatus getClusterStatus() throws InterruptedIOException {
+  public ClusterStatus getClusterStatusWithoutCoprocessor() throws InterruptedIOException {
     // Build Set of backup masters from ZK nodes
     List<String> backupMasterStrings;
     try {
@@ -3154,12 +3166,12 @@ public class HMaster extends HRegionServer implements MasterServices, Server {
 
   @Override
   public long getLastMajorCompactionTimestamp(TableName table) throws IOException {
-    return getClusterStatus().getLastMajorCompactionTsForTable(table);
+    return getClusterStatusWithoutCoprocessor().getLastMajorCompactionTsForTable(table);
   }
 
   @Override
   public long getLastMajorCompactionTimestampForRegion(byte[] regionName) throws IOException {
-    return getClusterStatus().getLastMajorCompactionTsForRegion(regionName);
+    return getClusterStatusWithoutCoprocessor().getLastMajorCompactionTsForRegion(regionName);
   }
 
   /**

hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterCoprocessorHost.java

@@ -27,6 +27,7 @@ import org.apache.commons.lang.ClassUtils;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.ClusterStatus;
 import org.apache.hadoop.hbase.Coprocessor;
 import org.apache.hadoop.hbase.HColumnDescriptor;
 import org.apache.hadoop.hbase.HRegionInfo;
@@ -919,7 +920,7 @@ public class MasterCoprocessorHost
       }
     });
   }
-  
+
   public void preCloneSnapshot(final SnapshotDescription snapshot,
       final HTableDescriptor hTableDescriptor) throws IOException {
     execOperation(coprocessors.isEmpty() ? null : new CoprocessorOperation() {
@@ -1071,7 +1072,7 @@ public class MasterCoprocessorHost
       }
     });
   }
-  
+
   public void preSetUserQuota(final String user, final Quotas quotas) throws IOException {
     execOperation(coprocessors.isEmpty() ? null : new CoprocessorOperation() {
       @Override
@@ -1166,7 +1167,7 @@ public class MasterCoprocessorHost
     });
   }
 
-  public void postSetNamespaceQuota(final String namespace, final Quotas quotas) 
+  public void postSetNamespaceQuota(final String namespace, final Quotas quotas)
       throws IOException {
     execOperation(coprocessors.isEmpty() ? null : new CoprocessorOperation() {
       @Override
@@ -1177,22 +1178,22 @@ public class MasterCoprocessorHost
     });
   }
 
-  public void preListDeadServers() throws IOException {
+  public void preGetClusterStatus() throws IOException {
     execOperation(coprocessors.isEmpty() ? null : new CoprocessorOperation() {
       @Override
       public void call(MasterObserver oserver, ObserverContext<MasterCoprocessorEnvironment> ctx)
               throws IOException {
-        oserver.preListDeadServers(ctx);
+        oserver.preGetClusterStatus(ctx);
       }
     });
   }
 
-  public void postListDeadServers() throws IOException {
+  public void postGetClusterStatus(final ClusterStatus status) throws IOException {
     execOperation(coprocessors.isEmpty() ? null : new CoprocessorOperation() {
       @Override
       public void call(MasterObserver oserver, ObserverContext<MasterCoprocessorEnvironment> ctx)
               throws IOException {
-        oserver.postListDeadServers(ctx);
+        oserver.postGetClusterStatus(ctx, status);
       }
     });
   }

hbase-server/src/main/java/org/apache/hadoop/hbase/master/MasterRpcServices.java

@@ -125,8 +125,6 @@ import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.IsRestoreSnapshot
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.IsRestoreSnapshotDoneResponse;
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.IsSnapshotDoneRequest;
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.IsSnapshotDoneResponse;
-import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.ListDeadServersRequest;
-import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.ListDeadServersResponse;
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.ListNamespaceDescriptorsRequest;
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.ListNamespaceDescriptorsResponse;
 import org.apache.hadoop.hbase.protobuf.generated.MasterProtos.ListProceduresRequest;
@@ -1140,33 +1138,6 @@ public class MasterRpcServices extends RSRpcServices
     }
   }
 
-  @Override
-  public ListDeadServersResponse listDeadServers(RpcController controller,
-      ListDeadServersRequest request) throws ServiceException {
-
-    LOG.debug(master.getClientIdAuditPrefix() + " list dead region servers.");
-    ListDeadServersResponse.Builder response = ListDeadServersResponse.newBuilder();
-    try {
-      master.checkInitialized();
-      if (master.cpHost != null) {
-        master.cpHost.preListDeadServers();
-      }
-
-      Set<ServerName> servers = master.getServerManager().getDeadServers().copyServerNames();
-      for (ServerName server : servers) {
-        response.addServerName(ProtobufUtil.toServerName(server));
-      }
-
-      if (master.cpHost != null) {
-        master.cpHost.postListDeadServers();
-      }
-    } catch (IOException io) {
-      throw new ServiceException(io);
-    }
-
-    return response.build();
-  }
-
   @Override
   public ClearDeadServersResponse clearDeadServers(RpcController controller,
       ClearDeadServersRequest request) throws ServiceException {

hbase-server/src/main/java/org/apache/hadoop/hbase/master/balancer/ClusterStatusChore.java

@@ -46,7 +46,7 @@ public class ClusterStatusChore extends ScheduledChore {
   @Override
   protected void chore() {
     try {
-      balancer.setClusterStatus(master.getClusterStatus());
+      balancer.setClusterStatus(master.getClusterStatusWithoutCoprocessor());
     } catch (InterruptedIOException e) {
       LOG.warn("Ignoring interruption", e);
     }

hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/AccessController.java

@@ -37,6 +37,7 @@ import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellScanner;
 import org.apache.hadoop.hbase.CellUtil;
+import org.apache.hadoop.hbase.ClusterStatus;
 import org.apache.hadoop.hbase.CompoundConfiguration;
 import org.apache.hadoop.hbase.CoprocessorEnvironment;
 import org.apache.hadoop.hbase.DoNotRetryIOException;
@@ -770,7 +771,7 @@ public class AccessController extends BaseMasterAndRegionObserver
           }
         }
       } else if (entry.getValue() == null) {
-        get.addFamily(col);        
+        get.addFamily(col);
       } else {
         throw new RuntimeException("Unhandled collection type " +
           entry.getValue().getClass().getName());
@@ -1338,7 +1339,7 @@ public class AccessController extends BaseMasterAndRegionObserver
       requirePermission("listSnapshot " + snapshot.getName(), Action.ADMIN);
     }
   }
-  
+
   @Override
   public void preCloneSnapshot(final ObserverContext<MasterCoprocessorEnvironment> ctx,
       final SnapshotDescription snapshot, final HTableDescriptor hTableDescriptor)
@@ -1412,7 +1413,7 @@ public class AccessController extends BaseMasterAndRegionObserver
   @Override
   public void preModifyNamespace(ObserverContext<MasterCoprocessorEnvironment> ctx,
       NamespaceDescriptor ns) throws IOException {
-    // We require only global permission so that 
+    // We require only global permission so that
     // a user with NS admin cannot altering namespace configurations. i.e. namespace quota
     requireGlobalPermission("modifyNamespace", Action.ADMIN, ns.getName());
   }
@@ -2605,14 +2606,6 @@ public class AccessController extends BaseMasterAndRegionObserver
       Action.ADMIN);
   }
 
-  @Override
-  public void preListDeadServers(ObserverContext<MasterCoprocessorEnvironment> ctx)
-      throws IOException { }
-
-  @Override
-  public void postListDeadServers(ObserverContext<MasterCoprocessorEnvironment> ctx)
-      throws IOException { }
-
   @Override
   public void preClearDeadServers(ObserverContext<MasterCoprocessorEnvironment> ctx)
       throws IOException {
@@ -2676,7 +2669,7 @@ public class AccessController extends BaseMasterAndRegionObserver
   public void postReplicateLogEntries(ObserverContext<RegionServerCoprocessorEnvironment> ctx,
       List<WALEntry> entries, CellScanner cells) throws IOException {
   }
-  
+
   @Override
   public void preSetUserQuota(final ObserverContext<MasterCoprocessorEnvironment> ctx,
       final String userName, final Quotas quotas) throws IOException {
@@ -2742,4 +2735,10 @@ public class AccessController extends BaseMasterAndRegionObserver
       String groupName) throws IOException {
     requirePermission("balanceRSGroup", Action.ADMIN);
   }
+
+  @Override
+  public void preGetClusterStatus(final ObserverContext<MasterCoprocessorEnvironment> ctx)
+      throws IOException {
+    requirePermission("getClusterStatus", Action.ADMIN);
+  }
 }

hbase-server/src/test/java/org/apache/hadoop/hbase/client/TestClientClusterStatus.java

@@ -0,0 +1,188 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.client;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicInteger;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.ClusterStatus;
+import org.apache.hadoop.hbase.HBaseConfiguration;
+import org.apache.hadoop.hbase.HBaseTestingUtility;
+import org.apache.hadoop.hbase.MiniHBaseCluster;
+import org.apache.hadoop.hbase.ServerName;
+import org.apache.hadoop.hbase.coprocessor.BaseMasterObserver;
+import org.apache.hadoop.hbase.coprocessor.CoprocessorHost;
+import org.apache.hadoop.hbase.coprocessor.MasterCoprocessorEnvironment;
+import org.apache.hadoop.hbase.coprocessor.ObserverContext;
+import org.apache.hadoop.hbase.master.HMaster;
+import org.apache.hadoop.hbase.regionserver.HRegionServer;
+import org.apache.hadoop.hbase.testclassification.SmallTests;
+import org.apache.hadoop.hbase.util.JVMClusterUtil.MasterThread;
+import org.apache.hadoop.hbase.util.JVMClusterUtil.RegionServerThread;
+import org.junit.AfterClass;
+import org.junit.Assert;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+/**
+ * Test the ClusterStatus.
+ */
+@Category(SmallTests.class)
+public class TestClientClusterStatus {
+  private static HBaseTestingUtility UTIL;
+  private static HBaseAdmin ADMIN;
+  private final static int SLAVES = 5;
+  private final static int MASTERS = 3;
+  private static MiniHBaseCluster CLUSTER;
+  private static HRegionServer DEAD;
+
+  @BeforeClass
+  public static void setUpBeforeClass() throws Exception {
+    Configuration conf = HBaseConfiguration.create();
+    conf.set(CoprocessorHost.MASTER_COPROCESSOR_CONF_KEY, MyObserver.class.getName());
+    UTIL = new HBaseTestingUtility(conf);
+    UTIL.startMiniCluster(MASTERS, SLAVES);
+    CLUSTER = UTIL.getHBaseCluster();
+    CLUSTER.waitForActiveAndReadyMaster();
+    ADMIN = UTIL.getHBaseAdmin();
+    // Kill one region server
+    List<RegionServerThread> rsts = CLUSTER.getLiveRegionServerThreads();
+    RegionServerThread rst = rsts.get(rsts.size() - 1);
+    DEAD = rst.getRegionServer();
+    DEAD.stop("Test dead servers status");
+    while (rst.isAlive()) {
+      Thread.sleep(500);
+    }
+  }
+
+  @Test
+  public void testDefaults() throws Exception {
+    ClusterStatus origin = ADMIN.getClusterStatus();
+    ClusterStatus defaults = ADMIN.getClusterStatus();
+    Assert.assertEquals(origin.getHBaseVersion(), defaults.getHBaseVersion());
+    Assert.assertEquals(origin.getClusterId(), defaults.getClusterId());
+    Assert.assertTrue(origin.getAverageLoad() == defaults.getAverageLoad());
+    Assert.assertTrue(origin.getBackupMastersSize() == defaults.getBackupMastersSize());
+    Assert.assertTrue(origin.getDeadServers() == defaults.getDeadServers());
+    Assert.assertTrue(origin.getRegionsCount() == defaults.getRegionsCount());
+    Assert.assertTrue(origin.getServersSize() == defaults.getServersSize());
+    Assert.assertTrue(origin.equals(defaults));
+  }
+
+
+  @Test
+  public void testLiveAndDeadServersStatus() throws Exception {
+    List<RegionServerThread> regionserverThreads = CLUSTER.getLiveRegionServerThreads();
+    int numRs = 0;
+    int len = regionserverThreads.size();
+    for (int i = 0; i < len; i++) {
+      if (regionserverThreads.get(i).isAlive()) {
+        numRs++;
+      }
+    }
+    // Retrieve live servers and dead servers info.
+    ClusterStatus status = ADMIN.getClusterStatus();
+    Assert.assertNotNull(status);
+    Assert.assertNotNull(status.getServers());
+    // exclude a dead region server
+    Assert.assertEquals(SLAVES -1, numRs);
+    // live servers = nums of regionservers
+    // By default, HMaster don't carry any regions so it won't report its load.
+    // Hence, it won't be in the server list.
+    Assert.assertEquals(status.getServers().size(), numRs);
+    Assert.assertTrue(status.getRegionsCount() > 0);
+    Assert.assertNotNull(status.getDeadServerNames());
+    Assert.assertEquals(1, status.getDeadServers());
+    ServerName deadServerName = status.getDeadServerNames().iterator().next();
+    Assert.assertEquals(DEAD.getServerName(), deadServerName);
+  }
+
+  @Test
+  public void testMasterAndBackupMastersStatus() throws Exception {
+    // get all the master threads
+    List<MasterThread> masterThreads = CLUSTER.getMasterThreads();
+    int numActive = 0;
+    int activeIndex = 0;
+    ServerName activeName = null;
+    HMaster active = null;
+    for (int i = 0; i < masterThreads.size(); i++) {
+      if (masterThreads.get(i).getMaster().isActiveMaster()) {
+        numActive++;
+        activeIndex = i;
+        active = masterThreads.get(activeIndex).getMaster();
+        activeName = active.getServerName();
+      }
+    }
+    Assert.assertNotNull(active);
+    Assert.assertEquals(1, numActive);
+    Assert.assertEquals(MASTERS, masterThreads.size());
+    // Retrieve master and backup masters infos only.
+    ClusterStatus status = ADMIN.getClusterStatus();
+    Assert.assertTrue(status.getMaster().equals(activeName));
+    Assert.assertEquals(MASTERS - 1, status.getBackupMastersSize());
+  }
+
+  @Test
+  public void testOtherStatusInfos() throws Exception {
+    ClusterStatus status = ADMIN.getClusterStatus();
+    Assert.assertTrue(status.getMasterCoprocessors().length == 1);
+    Assert.assertNotNull(status.getHBaseVersion());
+    Assert.assertNotNull(status.getClusterId());
+    Assert.assertNotNull(status.getBalancerOn());
+  }
+
+  @AfterClass
+  public static void tearDownAfterClass() throws Exception {
+    if (ADMIN != null) ADMIN.close();
+    UTIL.shutdownMiniCluster();
+  }
+
+  @Test
+  public void testObserver() throws IOException {
+    int preCount = MyObserver.PRE_COUNT.get();
+    int postCount = MyObserver.POST_COUNT.get();
+    boolean find = false;
+    for (String s : ADMIN.getClusterStatus().getMasterCoprocessors()) {
+      if (s.equals(MyObserver.class.getSimpleName())) {
+        find = true;
+      }
+    }
+    Assert.assertTrue(find);
+    Assert.assertEquals(preCount + 1, MyObserver.PRE_COUNT.get());
+    Assert.assertEquals(postCount + 1, MyObserver.POST_COUNT.get());
+  }
+
+  public static class MyObserver extends BaseMasterObserver {
+    private static final AtomicInteger PRE_COUNT = new AtomicInteger(0);
+    private static final AtomicInteger POST_COUNT = new AtomicInteger(0);
+
+
+    @Override
+    public void preGetClusterStatus(ObserverContext<MasterCoprocessorEnvironment> ctx)
+      throws IOException {
+      PRE_COUNT.incrementAndGet();
+    }
+
+    @Override public void postGetClusterStatus(ObserverContext<MasterCoprocessorEnvironment> ctx,
+      ClusterStatus status) throws IOException {
+      POST_COUNT.incrementAndGet();
+    }
+  }
+}

hbase-server/src/test/java/org/apache/hadoop/hbase/coprocessor/TestMasterObserver.java

@@ -36,6 +36,7 @@ import java.util.concurrent.CountDownLatch;
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.ClusterStatus;
 import org.apache.hadoop.hbase.CoprocessorEnvironment;
 import org.apache.hadoop.hbase.HBaseTestingUtility;
 import org.apache.hadoop.hbase.HColumnDescriptor;
@@ -272,13 +273,13 @@ public class TestMasterObserver {
     }
 
     @Override
-    public void preListDeadServers(ObserverContext<MasterCoprocessorEnvironment> ctx)
+    public void preGetClusterStatus(ObserverContext<MasterCoprocessorEnvironment> ctx)
         throws IOException {
     }
 
     @Override
-    public void postListDeadServers(ObserverContext<MasterCoprocessorEnvironment> ctx)
+    public void postGetClusterStatus(ObserverContext<MasterCoprocessorEnvironment> ctx,
-        throws IOException {
+        ClusterStatus status) throws IOException {
     }
 
     @Override

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestSplitTransactionOnCluster.java

@@ -1568,7 +1568,7 @@ public class TestSplitTransactionOnCluster {
     }
   }
 
-  private void waitUntilRegionServerDead() throws InterruptedException, InterruptedIOException {
+  private void waitUntilRegionServerDead() throws InterruptedException, IOException {
     // Wait until the master processes the RS shutdown
     for (int i=0; cluster.getMaster().getClusterStatus().
         getServers().size() > NB_SERVERS && i<100; i++) {

hbase-server/src/test/java/org/apache/hadoop/hbase/security/access/TestAccessController.java

@@ -3040,4 +3040,18 @@ public class TestAccessController extends SecureTestUtil {
     verifyAllowed(action1, SUPERUSER, USER_ADMIN);
     verifyDenied(action1, USER_CREATE, USER_RW, USER_RO, USER_NONE, USER_OWNER);
   }
+
+  @Test
+  public void testGetClusterStatus() throws Exception {
+    AccessTestAction action = new AccessTestAction() {
+      @Override
+      public Object run() throws Exception {
+      ACCESS_CONTROLLER.preGetClusterStatus(ObserverContext.createAndPrepare(CP_ENV, null));
+      return null;
+      }
+    };
+
+    verifyAllowed(action, SUPERUSER, USER_ADMIN);
+    verifyDenied(action, USER_CREATE, USER_RW, USER_RO, USER_NONE, USER_OWNER);
+  }
 }